The present invention relates to an industrial control system and, more particularly, to a method of controlling an industrial control system from which the overall system architecture and the operating parameters thereof may be conveniently modified by the system operator.
Typical industrial control systems include a plurality of diverse controlled devices and associated sensors that are interconnected and operably inter-related to achieve the desired system function. An exemplary industrial control system is one that controls the overall operation of a coal-fired electrical power generation installation. The controlled devices typically utilized in this type of application include motors, transmissions, valves, solenoids, pumps, compressors, clutches, etc., and the associated sensors typically include electrical energy responsive sensors, motion detectors, temperature and pressure detectors, timers, and the like. The controlled devices and the associated sensors are typically combined to form higher level sub-systems such as fuel feed systems, burner control systems, and pollution control and management sub-systems.
In the past, coordinated control of the various devices has been achieved by manually operated and various types of semi-automatic and automatic control systems including electromagnetic relay systems, hard-wired solid state logic systems, and various types of computer control systems. The computer systems have included central systems in which the various sensors and controlled deivices are connected to a central computer; distributed control systems in which a remotely located computer is connected to each of the controlled devices and to one another; and hybrid combinations of the central and distributed systems.
In each application where the system is under computer control, software must be provided to effect the desired sequential operation of the computer and consequent operation of the system. In general, software is generated by specialists who create the program in accordance with the system performance requirements. As part of this software generation, it is necessary to effect trial runs of the system during which time the software is "debugged". Likewise, when it is necessary to alter or otherwise modify the system operation, the software must be modified and debugged. In general, the procedure for writing software and the consequent debugging is both time consuming and expensive.
In order to provide for flexible operation of computer controlled industrial control systems and convenient modification of that control, there is a need for means by which the control system operator can quite readily alter the system configuration as well as change the operating parameters for the system or a sub-system portion thereof without the need for extensive software modification.